Base for turf system

Abstract

An underlayment layer is configured to support an artificial turf assembly. The underlayment layer comprises a core with a top side and a bottom side. The top side has a plurality of spaced apart, upwardly oriented projections that define channels suitable for fluid flow along the top side of the core when the underlayment layer is positioned beneath an overlying artificial turf assembly.

What is claimed is: 
     
       1. An artificial turf assembly comprising:
 an artificial turf carpet; and 
 a turf underlayment layer comprised of an assembly of panels, the panels including a top side and a bottom side, the top side including a plurality of drainage channels, the bottom side having a plurality of projections defining bottom side drainage channels, the top side configured to support the artificial turf carpet and one or more of the bottom side drainage channels extending across the bottom side in fluid communication with one or more of bottom side drainage channels of adjacent panels, and wherein the panels are made from a plurality of expanded polyolefin beads, the plurality of expanded polyolefin beads bonded together by at least one of pressure and heat to produce a substantially water-impervious surface. 
 
     
     
       2. The artificial turf assembly of  claim 1  wherein the panels define edges that interface with projections on two edges and form a panel interlock with adjoining panels on at least the other two edges. 
     
     
       3. The artificial turf assembly of  claim 2  wherein the panel interlock is one of a male and female jigsaw puzzle piece joint or a dovetail joint. 
     
     
       4. The artificial turf assembly of  claim 2  wherein the panel edges interfacing with projections include at least one panel interlock configured as one of a male and female jigsaw puzzle piece joint or a dovetail joint. 
     
     
       5. The artificial turf assembly of  claim 1  wherein the panels define a core comprising drain holes that fluidically connect at least one of the top side drainage channels to at least one of the bottom side drainage channels. 
     
     
       6. The artificial turf assembly of  claim 5  wherein the plurality of top side drainage channels are defined by a plurality of top side projections extending from the core. 
     
     
       7. The artificial turf assembly of  claim 6  wherein the plurality of top side projections are elongated projections that extend across the core. 
     
     
       8. The artificial turf assembly of  claim 1  wherein at least one of the bottom side drainage channels defines a channel opening that is wider at one of the panel edges than a bottom side channel width of the at least one bottom side drainage channel positioned away from the panel edge. 
     
     
       9. The artificial turf assembly of  claim 1  wherein the plurality of top side channels define intersection points and/or the plurality of bottom side channels define intersection points. 
     
     
       10. An artificial turf assembly comprising:
 an artificial turf carpet; and 
 a turf underlayment layer comprised of an assembly of panels, the panels including a core having a top side, a bottom side, and drainage holes extending through the core, the top side including a plurality of drainage channels, the bottom side having a plurality of projections defining bottom side drainage channels, the top side configured to support the artificial turf carpet and one or more of the bottom side drainage channels extending across the bottom side in fluid communication with one or more of bottom side drainage channels of adjacent panels, and wherein the panels are made from a plurality of expanded polyolefin beads, the plurality of expanded polyolefin beads bonded together by at least one of pressure and heat to produce a substantially water-impervious surface. 
 
     
     
       11. The artificial turf assembly of  claim 10  wherein the drainage holes connect the top side drainage channels for fluid communication with the bottom side drainage channels. 
     
     
       12. The artificial turf assembly of  claim 10  wherein the artificial turf carpet includes a backing layer, a plurality of fibers tufted onto the backing layer, and an infill material interspersed with the plurality of fibers. 
     
     
       13. The artificial turf assembly of  claim 12  wherein the artificial turf carpet and the underlayment layer provide one of a vertical ball rebound in a range of about 60 centimeters to about 100 centimeters when evaluated against European Committee for Standardization test specification EN 12235 or an angled ball behavior in a range of about 45% to about 70% when evaluated against European Committee for Standardization test specification EN 13865 or a vertical permeability greater than 180 mm/hr. when evaluated against European Committee for Standardization test specification EN 12616. 
     
     
       14. The artificial turf assembly of  claim 12  wherein the artificial turf carpet and the underlayment layer provide a shock absorption characteristic in a range of about 55% to about 70% when tested with a Berlin Artificial Athlete model. 
     
     
       15. The artificial turf assembly of  claim 10  supported by a foundation comprising one of asphalt, graded earth, compacted gravel or crushed rock to form an artificial turf system. 
     
     
       16. A artificial turf assembly comprising:
 an artificial turf carpet; and 
 a turf underlayment layer comprised of an assembly of panels, each of the panels formed from a plurality of expanded polyolefin beads, the plurality of expanded polyolefin beads bonded together by at least one of pressure and heat to produce a substantially water-impervious surface, the panels including a core having a top side and a bottom side, a plurality of projections extending from the top side and defining drainage channels across the top side, the panels including at least one panel interlock configured as one of a male or female jigsaw puzzle piece joint, or a dovetail recess, or a dovetail projection positioned on a perimeter edge of the panels that engage a mating male or female jigsaw puzzle piece joint, or a dovetail recess, or a dovetail projection on an adjacent panel of the assembly of panels, the panel interlock creating a spaced apart relationship between adjacent panels to accommodate one of vertical drainage or thermal expansion. 
 
     
     
       17. The artificial turf assembly of  claim 16  wherein the panel interlock includes at least one projection that is deformable to accommodate one of a snug fit relationship between adjoining panels or thermal expansion. 
     
     
       18. The artificial turf assembly of  claim 16  wherein the projections extending from the top surface are one of a square geometry or a round geometry. 
     
     
       19. The artificial turf assembly of  claim 18  wherein the projections extending from the top surface define tapered sides. 
     
     
       20. The artificial turf assembly of  claim 16  wherein the bottom side includes a plurality of drainage channels that extend to the panel perimeter edge. 
     
     
       21. The artificial turf assembly of  claim 20  wherein a plurality of projections extend from the bottom side of the core and define the bottom side drainage channels. 
     
     
       22. The artificial turf assembly of  claim 21  wherein the core includes a plurality of drainage holes that provide fluid communication between the top side and the bottom side. 
     
     
       23. An artificial turf assembly comprising:
 an artificial turf carpet having a backing layer and a plurality of fibers tufted onto the backing layer; 
 a turf underlayment layer comprised of an assembly of panels, each of the panels formed from a plurality of expanded polyolefin beads, the plurality of expanded polyolefin beads bonded together by at least one of pressure and heat to produce a substantially water-impervious surface, the panels including a core having a top side and a bottom side, a plurality of projections extending from the top side and defining drainage channels across the top side, wherein at least one of the plurality of projections or the drainage channels has a textured surface configured as one of bumps, or raised nibs, or dots. 
 
     
     
       24. The artificial turf assembly of  claim 23  wherein the artificial turf carpet includes an infill material interspersed with the plurality of fibers, the artificial turf carpet and infill material interacting with the turf underlayment layer to provide an impact response characteristic in a range of about 55% to about 70% shock absorption and about 4 millimeters to about 9 millimeters of deformation, when tested with a Berlin Artificial Athlete model. 
     
     
       25. The artificial turf assembly of  claim 23  wherein the plurality of top side projections are one of a square geometry or an elongated projection extending across the top side. 
     
     
       26. The artificial turf assembly of  claim 23  wherein the bottom side of the panel comprises bottom side drainage channels. 
     
     
       27. The artificial turf assembly of  claim 26  wherein at least one of the bottom side drainage channel of at least one panel of the assembly of panels is in fluid communication with at least one bottom side drainage channel of an adjacent panel of the assembly of panels. 
     
     
       28. The artificial turf assembly of  claim 23  wherein the bottom side of at least one panel of the assembly of panels includes a plurality of projections that define bottom side drainage channels. 
     
     
       29. The artificial turf assembly of  claim 23  wherein each panel has a material density in a range of about 45 grams per liter to about 70 grams per liter. 
     
     
       30. The artificial turf assembly of  claim 23  wherein each panel has edges and at least one edge of at least one panel is configured to define a gap between at least one edge of an adjacent panel of the assembly of panels, the gap configured to provide at least one of fluid communication between the top side of the at least one panel and the bottom side of the adjacent panel or accommodate thermal expansion between the one panel and the adjacent panel.